The Norwegian was top of the pile for the 12th time out of 21 World Cup events as he finished with a total time of 25:14.9.
Riiber was second after the jumping with 121.7 points and crossed the line sixth in the cross country to confirm his triumph, finishing 25 seconds clear of compatriot Jan Schmid in Germany.
He finishes his 2018/19 World Cup campaign with 1518 points, well clear of overall second-place Akito Watabe, from Japan, who ended up with 893 points after a fifth-placed finish in Schonach.
Ruthless Riiber ends campaign on a high after claiming third Crystal Globe
21/03/2021 AT 15:46
The podium was rounded off by Austrian Bernhard Gruber as he crossed the line 38.2 seconds after Riiber.
Riiber claims 10km glory in Klingenthal
21/03/2021 AT 14:26
Nordic Combined
Teenager Lamparter makes Nordic Combined history
06/03/2021 AT 18:49